Light

Point

This is a simple point light shader emitting light uniformly in all directions.

mib_light_point

    color "mib_light_point" (
        color           "color",
        boolean         "shadow",
        scalar          "factor",
        boolean         "atten",
        scalar          "start",
        scalar          "stop")

color: is the light color.
shadow: if true, enables shadows. The light will be diminished or blocked by occluding objects between the light and the illuminated object.
factor: only has an effect if shadows are enabled, and blends from the shadow color (0, the default) to the light color (1). Effectively, values greater than 0 let the light penetrate occluding objects. At 1, no shadows appear.
atten: if true, enables distance attenuation such that the light intensity begins to fall off at the distance start and fades up the distance stop, where no light remains.
start: only has an effect if distance attenuation is enabled. It specifies the distance from the light where attenuation begins.
stop: only has an effect if distance attenuation is enabled. It specifies the maximum distance reached by the light.

Spot

The spot light is similar to the point light, except that it also supports angle attenuation based on the light direction. It takes the light direction and the spread (the cosine of the outer boundary angle) from the light definition.

mib_light_spot

    color "mib_light_spot" (
        color           "color",
        boolean         "shadow",
        scalar          "factor",
        boolean         "atten",
        scalar          "start",
        scalar          "stop",
        scalar          "cone")

color: is the light color.
shadow: if true, enables shadows. The light will be diminished or blocked by occluding objects between the light and the illuminated object.
factor: only has an effect if shadows are enabled, and blends from the shadow color (0, the default) to the light color (1). Effectively, values greater than 0 let the light penetrate occluding objects. At 1, no shadows appear.
atten: if true, enables distance attenuation such that the light intensity begins to fall off at the distance start and fades up the distance stop, where no light remains.
start: only has an effect if distance attenuation is enabled. It specifies the distance from the light where attenuation begins.
stop: only has an effect if distance attenuation is enabled. It specifies the maximum distance reached by the light.
cone: specifies the cosine of the angle of the inner cone that illuminates with full intensity, in degrees. The value must be in the range 0 (hemisphere) to 1 (null diameter). The cone cannot exceed the spread angle from the light definition.

Infinite

Infinite (directional) lights cast parallel rays in the light direction. The origin is infinitely far away (and left unspecified), and there is no distance attenuation.

mib_light_infinite

    color "mib_light_infinite" (
        color           "color",
        boolean         "shadow",
        scalar          "factor")

color: is the light color.
shadow: if true, enables shadows. The light will be diminished or blocked by occluding objects between the light and the illuminated object.
factor: only has an effect if shadows are enabled, and blends from the shadow color (0, the default) to the light color (1). Effectively, values greater than 0 let the light penetrate occluding objects. At 1, no shadows appear.

Photometric

This is a variation of a simple point light shader emitting light according to the distribution determined by a light profile. This shader also honors the decay rate.

mib_light_photometric

    color "mib_light_photometric" (
        color           "color",
        boolean         "shadow",
        scalar          "factor",
        boolean         "atten",
        scalar          "start",
        scalar          "stop",
        lightprofile    "profile")

color: is the light color.
shadow: if true, enables shadows. The light will be diminished or blocked by occluding objects between the light and the illuminated object.
factor: only has an effect if shadows are enabled, and blends from the shadow color (0, the default) to the light color (1). Effectively, values greater than 0 let the light penetrate occluding objects. At 1, no shadows appear.
atten: if true, enables distance attenuation such that the light intensity begins to fall off at the distance start and fades up the distance stop, where no light remains.
start: only has an effect if distance attenuation is enabled. It specifies the distance from the light where attenuation begins.
profile: is a light profile describing the intensity distribution of the light with respect to the emission direction. If no light profile is provided the light behaves like a uniform point light.